Setting up a new aquarium is an exciting process, but it is crucial to get the nitrogen cycle started setting up a new tank. This process is vital for keeping your fish healthy and ensuring your tank’s ecosystem remains stable. Let’s dive into the basics of the nitrogen cycle and everything you need to know to set up your new tank!

What is New Tank Syndrome?

New Tank Syndrome is what happens in a new aquarium when there isn’t enough beneficial bacteria to break down the toxic waste from fish, food, and plant matter. In the wild, waste products get diluted or washed away, but in a closed system like an aquarium, this waste builds up quickly, creating ammonia and other harmful toxins. Without intervention, these toxins can reach deadly levels, especially during the first few weeks.

What is the Nitrogen Cycle in Aquariums?

The nitrogen cycle is a biological process carried out by beneficial bacteria that grow in the tank’s filter and substrate. These bacteria convert harmful ammonia from fish waste and leftover food into nitrites, and then into nitrates, which are far less toxic for fish. This cycle makes the tank water safer for your fish, but it takes time to establish and needs monitoring along the way.

How Long Does It Take for an Aquarium to Cycle?

On average, it takes around 6-8 weeks for a new tank to cycle completely. During this period, beneficial bacteria build up in the filter and substrate, getting strong enough to handle the waste in the tank. However, various factors can influence the cycling speed, and certain products or techniques can help you speed up the process if needed.

Stages of the Cycle

The nitrogen cycle in an aquarium has three main stages, each crucial for maintaining a safe, balanced environment.

Nitrate

Nitrate (NO3) is the final stage and is much less toxic to fish in low amounts. Beneficial bacteria, such as Nitrobacter, convert nitrites into nitrates. Although less dangerous, nitrate levels should still be monitored and kept low with regular water changes and by using plants that naturally absorb nitrates.

How to Cycle Your Aquarium

There are two primary methods to cycle a tank: the fish-in cycle and the fishless cycle. Here’s how to cycle your aquarium using both methods.

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Fish-In Cycle: Cycling With Fish

While not the ideal method, some people choose to cycle their tank with fish. This method exposes the fish to ammonia and nitrites during the cycling process, which can stress them out. However, it’s possible if done carefully.

Steps for a Fish-In Cycle:

1. Choose Hardy Fish: Select hardy fish like zebra danios or guppies, which can tolerate fluctuations in water quality.
2. Test Your Water Regularly: Use a test kit to check for ammonia, nitrites, and nitrates. This will help you track the progress of the cycle.
3. Monitor Ammonia and Nitrites: During the cycle, ammonia and nitrite levels will spike. Do daily water changes (about 20%) to keep levels low and prevent fish stress.
4. Add Fish Slowly: Don’t overload your tank with fish right away. Add a few at a time to avoid overloading the filtration system.
   Acclimation Guide
5. Use Bacteria Starters: Adding a bacteria starter product can help speed up the growth of the beneficial bacteria that will break down ammonia and nitrites.
6. Wait for the Cycle to Complete: The fish-in cycle can take longer and may cause stress for your fish, but when you see ammonia and nitrite levels drop to zero and nitrates appear, your tank is cycled.

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Fishless Cycle: Cycling Without Fish

The fishless cycle is the preferred and safest method since it avoids exposing fish to toxic compounds. Instead of fish waste, you’ll add ammonia manually to simulate the biological load.

Steps for a Fishless Cycle:

1. Add Ammonia to the Tank: You can use pure ammonia (without additives or fragrances) or drop in some fish food to break down and release ammonia. Add enough ammonia to raise the level to about 3 ppm (parts per million).
2. Test the Water: Use your test kit to check ammonia levels. The goal is to see ammonia levels rise and then gradually decrease as bacteria start converting it into nitrites.
3. Wait for Nitrite Levels to Appear: After a few days or weeks, you should start seeing nitrites. When this happens, the bacteria that convert ammonia to nitrites have colonized your tank.
4. Add More Ammonia: Once you see nitrites, continue adding small amounts of ammonia daily to feed the bacteria and keep the cycle going. Slowly reduce the amount of ammonia added once you start seeing nitrates.
5. Wait for Nitrates to Appear: Eventually, you’ll notice nitrates building up. This means the cycle is nearly complete.
6. Perform a Water Change: Once nitrates are present, do a large water change (about 30%) to lower nitrate levels to a safe range.
7. Introduce Fish Slowly: Now that your tank is cycled, you can add fish slowly. Be sure to test the water regularly to ensure everything is stable.
   Acclimation Guide

How Do I Increase My Biological Filtration?

Increasing biological filtration means providing more surfaces for beneficial bacteria to grow. You can do this by:

1. Adding high-quality filter media like sponge filters, ceramic rings, or bio-balls that offer more surface area.
2. Using a larger filter than what’s strictly needed for your tank size.
3. Adding live plants which absorb nitrogen compounds, providing natural filtration.

Speeding up the Cycling Process

Want to speed up the cycling process? Here are some methods that can help:

• Bacteria Starters: Products like Fast Filter Start contain live bacteria, which can help establish the nitrogen cycle faster.
• Use Filter Media from an Established Tank: If you have access to an already cycled tank, borrow some filter media or substrate to “seed” your new tank with beneficial bacteria.
• Increase Tank Temperature: Warming the water to about 80°F (27°C) can encourage bacteria to multiply faster.
• Add Plants: Plants absorb nitrates and provide surfaces for bacteria to grow.

Plants

Aquatic plants are a natural way to control nitrates in your tank. Plants use nitrogen as a nutrient, helping to keep nitrate levels low. They also provide surface area for beneficial bacteria to colonize. If possible, add live plants to your tank to help maintain a balanced ecosystem.
Plants that breach the waters surface and grow fast are best as the absorb nitrates at a higher rate.

Water Changes

Regular water changes are essential, changing 20% of the water each week helps dilute toxins and gives your fish a break from any build-up of harmful compounds. Remember to use chlorinated water or tap water treated with a water conditioner to avoid killing beneficial bacteria.

How to Avoid Breaking the Cycle

After the cycle is established, it’s important to maintain it. Here’s how to avoid disrupting the nitrogen cycle:

• Avoid over-cleaning the filter media; rinsing it in tank water instead of tap water helps retain beneficial bacteria.
• Don’t overstock the tank too quickly, as this can increase waste beyond what the bacteria can handle.
• Feed sparingly to prevent excessive waste.

These steps ensure your tank’s bacteria colonies remain stable and can handle the bio-load in your tank.

FAQs about Acclimation

Q: How do I know if my tank has finished cycling?
A: Test your water regularly. When you see ammonia and nitrite levels drop to zero and a low level of nitrates appear, your tank is likely cycled and ready for fish.

Q: Can I add all my fish at once?
A: No, it’s best to add a few fish at a time, allowing bacteria colonies to adjust to the increased bio-load.

Q: Can plants break the cycle?
A: No, plants actually help by absorbing nitrates and supporting bacteria colonies on their surfaces.

Q: Do I need a heater during cycling?
A: It depends on the fish you plan to keep, but a higher temperature around 26°c can speed up bacterial growth, which may help the cycle complete faster.